Tillage depends on the whys and how of need

November 19, 2009

Now that most of the crops are out of the fields, farmers have another worry: whether to till the ground now or wait until spring.

It's not so much when you till as how and why you till, say Jodi Dejong Hughes, University of Minnesota Extension educator, and DeLon Clarksean, field agronomist at Farmers Co-op Association in Canby.

"For the most part, if they can scratch their way through, fall is preferable for tilling," said Clarksean.

Article Photos

Photo by Rae KrugerFran Deutz works in a field near Marshall Wednesday morning.

"To spread out the risk, they should try to get as many fields as they can this fall and leave the rest until spring," Hughes said.

Not tilling in the fall is less work, Hughes said, but you hang your hopes on the fact it won't be as wet in the spring.

"Leaving all your tillage is leaving too many eggs in one basket," she warned.

It also depends on what you want to put in that ground come spring, they said.

"Soybeans can take different residue levels and can be no till," Hughes said. "That gives them more options."

"Corn, especially when you get to spring, you need to have three to four inches of residue-free soil," Clarksean said. "In our cold spring this year, any residue in that seed track kept soil cooler and delays emergence."

"Start to warm up that soil," Hughes advised. "Corn is much more sensitive to soil temperatures."

"Wheat doesn't need as much tillage and you can plant that earlier," Hughes said.

Farmers also need to consider field conditions and how they are tilling.

"The wetter it is, the shallower you should keep your equipment," Hughes said. "Now, run vertical till equipment over it, just blacken the soil a bit and incorporate some residue."

Clarksean agreed the shallower the better.

"The problem with going really deep is you'll get side-wall smearing as the tool goes through," he said. "You'll create restriction problems, horizontally as well as laterally."

That's not the only problem farmers could create for themselves.

"Some of the fields shouldn't be tilled right now," Hughes said. "They're bringing up slabs of soil that will take one or two passes in the spring to break. They'll be lucky if it only takes one. If we have a dry spring, those slabs will turn into rocks. Then they will have a hard time getting those made into a seed bed."

Equipment can help create the problem.

"They need to minimize their compaction," Hughes said, adding they should do everything they can to keep the tractor as light as possible. "Properly inflate tires. Consider the suitcases on front. Take any extra weight off the combines. Unload grain more often."

Avoiding compaction is imperative, Clarksean said.

"Once you're got compaction in the field, you've got it for awhile," he said. "It's not going to go away overnight." He knows of some farmers who have been fighting compaction for 10 or 15 years.

What kind of soil you have can make a big difference, too, Clarksean said.

"The heavier clay type soils present more of a challenge," he said. "Loams or sandy soils are a lot more forgiving. In Minnesota, we've got it all in the same acre."